Yeah, making semi-administrative changes to your own account triggers that problem. (New members can't register with banned domains, but old accounts haven't been forcibly changed. It just generates errors when you try to adjust related settings.)

If you change your E-mail address to a domain that isn't banned, you'll be able to make those other changes as well. And if you don't have something to which you can change it (like a college or work address), I'd suggest contacting Chris.